The present invention relates to a disk brake for a vehicle, in particular a commercial vehicle, having a brake application device which is arranged in a brake caliper and by way of which a brake lining can be pressed against a brake disk during braking via at least one or two control spindles which are arranged in a bridge in parallel and at a distance from one another.
The brake application device has a cylindrical roller, which is in contact with a rotary lever of the brake application device, which lever is configured as an eccentric in the supporting region with rotary bearings of the brake caliper. The cylindrical roller is fastened in an axially and radially secured manner as a separate component, and the cylindrical roller is held by a cylindrical roller holder which is fastened to the lever.
In a disk brake of the above type, which can preferably be actuated by compressed air or electronically and can be installed, in particular, in commercial vehicles, the brake application device includes the rotary lever, a bearing shell which is connected to the lever, and the cylindrical roller, which extends parallel to the brake disk and forms a pivot axis for the lever. The cylindrical roller lies in the bearing shell.
For the axial and radial fixing of the cylindrical roller, it is known to provide bearing lugs on the bridge, which are usually formed from sheet metal and in which the cylindrical roller is held. Together with a correspondingly shaped contact face, the bearing shell, which is riveted to the lever and is likewise composed of sheet metal, forms the bearing for the cylindrical roller.
However, disadvantages result, in particular during assembly. The assembly proves to be complicated and, therefore, counterproductive to economic and inexpensive manufacturing.
As assemblies are preinstalled, which are joined together during final assembly, every assembly which is to be manufactured separately is associated with corresponding manufacturing expenditures together with the costs which result from that.
The known disk brake also leaves something to be desired in functional terms, as exact positioning of the cylindrical roller with respect to the lever by the fastening of the cylindrical roller to the bridge is not ensured.
A disk brake of the above type is known from U.S. Pat. No. 6,311,809 B1, in which the lever is supported on rotational bearings, which are in contact with the brake caliper. As the brake actuation increases, there is the risk that the rotational bearings, which are configured as needle bearings, are guided out of their contact region, with the result that the functionality is at least restricted.
The present invention is, therefore, based on the object of developing a disk brake of the generic type in such a way that it can be manufactured more inexpensively while improving its function.
This object is achieved by providing a disk brake having a brake application device which is arranged in a brake caliper and by way of which a brake lining can be pressed against a brake disk during braking via at least one or two control spindles which are arranged in a bridge in parallel and at a distance from one another.
The brake application device has a cylindrical roller, which is in contact with a rotary lever of the brake application device, which lever is configured as an eccentric in the supporting region with rotary bearings of the brake caliper. The cylindrical roller is fastened in an axially and radially secured manner as a separate component, and the cylindrical roller is held by a cylindrical roller holder which is fastened to the lever.
The cylindrical roller holder is provided with cage return guides, by way of which, when the rotary lever pivots back into an initial position, the rotational bearings can likewise be pressed back into an initial position.
As a result of this structural configuration of a disk brake, the lever assembly can be preinstalled as a complete unit, while there is then no more installation work to be performed in this sense on other components, for example the bridge assembly. This naturally results in manufacturing advantages, because it is possible to dispense completely with installation processing of the bridge.
The invention is of particular significance, in particular, in view of disk brakes of this type being manufactured in great numbers.
This applies equally to final installation, in which the disk brakes are assembled. Here too, there is a simplification in the work sequence with the consequence of an appreciable reduction in costs.
The functionality of the disk brake is also improved by the refinement according to the invention, as it is possible to position the cylindrical roller very precisely with respect to the lever. As a result, tolerance-induced actuating problems of the brake application device are avoided overall and, as a result of which, the functional reliability of the disk brake is increased.
According to one advantageous aspect of the invention, there is provision for, in each case, one bearing lug to be provided at the end, preferably at both ends, of the bearing shell, which is riveted to the lever. A bearing journal, which is attached concentrically at the respective end of the cylindrical roller, lies in said bearing lug.
The bearing shell is usually formed from sheet metal, preferably as a punched part, with the result that it is possible to attach the bearing lugs without additional manufacturing expenditure, that is to say the bearing lugs can also be formed during punching of the bearing shell.
Particularly simple assembly results if, in order to fasten the cylindrical roller to the lever, a separate cylindrical roller holder is provided which holds the cylindrical roller in the region of the bearing journals on the side which lies opposite the bearing shell. The cylindrical roller holder is, moreover, connected fixedly to the lever, for example by riveting.
The cylindrical roller holder can be configured such that it at the same time assumes the function of the return guide for rotational bearing cages. The rotatable lever is mounted on a brake caliper using the rotational bearing cages.
In the case where, given an appropriate design of the disk brake, rotational bearings are used, a single component may be used as the return guide for the cages and to hold the cylindrical roller. The single component can both be manufactured as a simple punched sheet metal part and can also be assembled with little expenditure.
Further advantageous configurations of the invention are described and claimed herein.